[ofa-general] PATCH [0/3] osm: adding root and compute node guid files options for fat-tree

[Yevgeny Kliteynik]

Sasha Khapyorsky wrote:
> Hi Yevgeny,
> 
> On 11:19 Thu 14 Jun     , Yevgeny Kliteynik wrote:
>>  The following three patches are adding root and compute node guid files
>>  options for fat-tree routing,
> 
> Is there any reason to not share root guids file option with up/down?

There are two new options for fat-tree: roots and compute nodes (CN).
These two will be very "tightly coupled" and would have more implication
on the routing than in case of up/dn roots. For instance, having root
file but not CN file means that the topology doesn't have to be pure fat-tree,
but all the CAs are considered CNs and have to be on the same level of the tree.
And there is similar implication of all the combinations of these two options.

Because of this coupling I wanted to differentiate these two options from
the up/dn roots.

Thoughts?
 
> Also the way how root guids are handled (in both up/down and ftree)
> doesn't look very optimal - guids are loaded to dynamic list, the list
> is converted to map, this map is matched and root nodes are marked as
> roots. Isn't it would be easy just to mark root nodes during file 
> parsing?

The only thing you can save here is converting list to map:
You have to parse the guids file anyway, and you have to build all the
fat-tree data structures anyway. So if you parse the file and fill the
map right away instead of filling the list first, you will save the 
list2map conversion.
But then up/dn and fat-tree can't use the same function to parse the guid file,
and since the list2map conversion is not a big deal (we're talking about list
of roots, which is couple of hundreds of guids at max), I prefer to leave it
and not to use separate parsing functions for up/dn and fat-tree.

BTW, since we're on this subject, how about removing the list2array conversion
in the same place in up/dn routing?

-- Yevgeny
 
> Sasha
>